Spain's Second Deputy Prime Minister and Labour Minister, Yolanda Díaz, has launched a bid to become the country's first female PM.

Díaz declared her bid to run for the upcoming general elections set to take place at the end of the year, in front of over 3,000 supporters in Madrid, with the incumbent coalition government hoping to win another four-year term. 

"Today, I am humbly taking a step forward. Today, I want to become our country's first female prime minister," Díaz stated.  

Sunday's rally in Madrid featured allies from Díaz's own Communist party as well as LGBT and feminist activists, and the mayors of Barcelona and Valencia, Reuters reports. However, not in attendance was the Podemos leadership, a party with messaging akin to Diaz's new Sumar ('Unite') initiative. 

Spanish local and regional elections taking place next month could act as a guide to determine Podemos' electoral appeal, swaying decisions on reaching a campaign deal with Sumar or launching a separate bid, the Reuters report adds. 

Díaz has unveiled the wider outline of her manifesto, which includes a new "bill of rights" and a democratic, economic and social "contract" for the next decade. 

In addition, Díaz plugged her ministry's achievements, including a pro-union labour law reform and minimum wage hike.

As per a recent survey carried out by the Centre for Sociological Studies, Díaz is the Spanish politician with the highest approval rating, averaging 4.89 out of 10. 

Moreover, political consultant and professor at the University of Valladolid Alicia Gil-Torres said of Díaz: "When she takes on her opponents in Congress, people see a woman who knows how to hold a political debate, who backs herself up with data," Financial Times reports.